Revert of [debugger] flood function for stepping before calling it.

src/mips64/macro-assembler-mips64.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <limits.h>  // For LONG_MIN, LONG_MAX.
 
 #if V8_TARGET_ARCH_MIPS64
 
 #include "src/base/division-by-constant.h"
 #include "src/bootstrapper.h"
@@ skipping 4229 matching lines @@
         Branch(done);
       }
     } else {
       Jump(adaptor, RelocInfo::CODE_TARGET);
     }
     bind(&regular_invoke);
   }
 }
 
 
-void MacroAssembler::FloodFunctionIfStepping(Register fun, Register new_target,
-                                             const ParameterCount& expected,
-                                             const ParameterCount& actual) {
-  Label skip_flooding;
-  ExternalReference debug_step_action =
-      ExternalReference::debug_last_step_action_address(isolate());
-  li(t0, Operand(debug_step_action));
-  lb(t0, MemOperand(t0));
-  Branch(&skip_flooding, ne, t0, Operand(StepIn));
-  {
-    FrameScope frame(this,
-                     has_frame() ? StackFrame::NONE : StackFrame::INTERNAL);
-    if (expected.is_reg()) {
-      SmiTag(expected.reg());
-      Push(expected.reg());
-    }
-    if (actual.is_reg()) {
-      SmiTag(actual.reg());
-      Push(actual.reg());
-    }
-    if (new_target.is_valid()) {
-      Push(new_target);
-    }
-    Push(fun);
-    Push(fun);
-    CallRuntime(Runtime::kDebugPrepareStepInIfStepping, 1);
-    Pop(fun);
-    if (new_target.is_valid()) {
-      Pop(new_target);
-    }
-    if (actual.is_reg()) {
-      Pop(actual.reg());
-      SmiUntag(actual.reg());
-    }
-    if (expected.is_reg()) {
-      Pop(expected.reg());
-      SmiUntag(expected.reg());
-    }
-  }
-  bind(&skip_flooding);
-}
-
-
-void MacroAssembler::InvokeFunctionCode(Register function, Register new_target,
-                                        const ParameterCount& expected,
-                                        const ParameterCount& actual,
-                                        InvokeFlag flag,
-                                        const CallWrapper& call_wrapper) {
+void MacroAssembler::InvokeCode(Register code,
+                                Register new_target,
+                                const ParameterCount& expected,
+                                const ParameterCount& actual,
+                                InvokeFlag flag,
+                                const CallWrapper& call_wrapper) {
   // You can't call a function without a valid frame.
   DCHECK(flag == JUMP_FUNCTION || has_frame());
-  DCHECK(function.is(a1));
+
+  // Ensure new target is passed in the correct register. Otherwise clear the
+  // appropriate register in case new target is not given.
   DCHECK_IMPLIES(new_target.is_valid(), new_target.is(a3));
-
-  if (call_wrapper.NeedsDebugStepCheck()) {
-    FloodFunctionIfStepping(function, new_target, expected, actual);
-  }
-
-  // Clear the new.target register if not given.
   if (!new_target.is_valid()) {
     LoadRoot(a3, Heap::kUndefinedValueRootIndex);
   }
 
   Label done;
   bool definitely_mismatches = false;
   InvokePrologue(expected, actual, &done, &definitely_mismatches, flag,
                  call_wrapper);
   if (!definitely_mismatches) {
-    // We call indirectly through the code field in the function to
-    // allow recompilation to take effect without changing any of the
-    // call sites.
-    Register code = t0;
-    ld(code, FieldMemOperand(function, JSFunction::kCodeEntryOffset));
     if (flag == CALL_FUNCTION) {
       call_wrapper.BeforeCall(CallSize(code));
       Call(code);
       call_wrapper.AfterCall();
     } else {
       DCHECK(flag == JUMP_FUNCTION);
       Jump(code);
     }
     // Continue here if InvokePrologue does handle the invocation due to
     // mismatched parameter counts.
     bind(&done);
   }
 }
 
 
 void MacroAssembler::InvokeFunction(Register function,
                                     Register new_target,
                                     const ParameterCount& actual,
                                     InvokeFlag flag,
                                     const CallWrapper& call_wrapper) {
   // You can't call a function without a valid frame.
   DCHECK(flag == JUMP_FUNCTION || has_frame());
 
   // Contract with called JS functions requires that function is passed in a1.
   DCHECK(function.is(a1));
   Register expected_reg = a2;
-  Register temp_reg = t0;
-  ld(temp_reg, FieldMemOperand(a1, JSFunction::kSharedFunctionInfoOffset));
+  Register code_reg = t0;
+  ld(code_reg, FieldMemOperand(a1, JSFunction::kSharedFunctionInfoOffset));
   ld(cp, FieldMemOperand(a1, JSFunction::kContextOffset));
   // The argument count is stored as int32_t on 64-bit platforms.
   // TODO(plind): Smi on 32-bit platforms.
   lw(expected_reg,
-     FieldMemOperand(temp_reg,
-                     SharedFunctionInfo::kFormalParameterCountOffset));
+      FieldMemOperand(code_reg,
+                      SharedFunctionInfo::kFormalParameterCountOffset));
+  ld(code_reg, FieldMemOperand(a1, JSFunction::kCodeEntryOffset));
   ParameterCount expected(expected_reg);
-  InvokeFunctionCode(a1, new_target, expected, actual, flag, call_wrapper);
+  InvokeCode(code_reg, new_target, expected, actual, flag, call_wrapper);
 }
 
 
 void MacroAssembler::InvokeFunction(Register function,
                                     const ParameterCount& expected,
                                     const ParameterCount& actual,
                                     InvokeFlag flag,
                                     const CallWrapper& call_wrapper) {
   // You can't call a function without a valid frame.
   DCHECK(flag == JUMP_FUNCTION || has_frame());
 
   // Contract with called JS functions requires that function is passed in a1.
   DCHECK(function.is(a1));
 
   // Get the function and setup the context.
   ld(cp, FieldMemOperand(a1, JSFunction::kContextOffset));
 
-  InvokeFunctionCode(a1, no_reg, expected, actual, flag, call_wrapper);
+  // We call indirectly through the code field in the function to
+  // allow recompilation to take effect without changing any of the
+  // call sites.
+  ld(t0, FieldMemOperand(a1, JSFunction::kCodeEntryOffset));
+  InvokeCode(t0, no_reg, expected, actual, flag, call_wrapper);
 }
 
 
 void MacroAssembler::InvokeFunction(Handle<JSFunction> function,
                                     const ParameterCount& expected,
                                     const ParameterCount& actual,
                                     InvokeFlag flag,
                                     const CallWrapper& call_wrapper) {
   li(a1, function);
   InvokeFunction(a1, expected, actual, flag, call_wrapper);
@@ skipping 1924 matching lines @@
   if (mag.shift > 0) sra(result, result, mag.shift);
   srl(at, dividend, 31);
   Addu(result, result, Operand(at));
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_MIPS64